<div class="control-group">
    <?php echo CHtml::dropDownList('block['.$index.'][id]', $model->block_id, CHtml::listData($blocks, 'block_id', 'name')) ?>

    <?php echo CHtml::hiddenField('block['.$index.'][region]', $model->region) ?>

    <input type="button" class="btn btn-danger removeBlock" value="Remove" />
</div>